Related papers: Rotation and activity in late-type members of the …

$\delta$ Scuti stars are hot, rapid rotators and are a poorly understood class of pulsators. Asteroseismology provides the only means with which to probe their interior dynamics. However, their complex and unexplained oscillation patterns…

We analyze Keck Hires observations of rotation in F, G, and K dwarf members of the open cluster M34 (NGC 1039), which is 250 Myr old, and we compare them to the Pleiades, Hyades, and NGC 6475. The upper bound to rotation seen in M34 is…

We derive the effective temperatures and gravities of 461 OB stars in 19 young clusters by fitting the H-gamma profile in their spectra. We use synthetic model profiles for rotating stars to develop a method to estimate the polar gravity…

In this paper, we analyze 10 globular clusters in order to measure their rotational properties by using high precision radial velocity data from the SDSS-IV APOGEE-2 survey. Out of the 10 clusters we were able to successfully measure the…

Recent space-based missions have ushered in a new era of observational astronomy, where high-cadence photometric light curves for thousands to millions of stars in the solar neighborhood can be used to test and apply stellar age-dating…

Cool star rotation periods have become an important tool in determining ages of open clusters. We aim to estimate the age of the open cluster NGC 2281 based on the rotational properties of its low-mass members. Previous age estimates for…

The Tucana-Horologium Association (Tuc-Hor) is a 40 Myr old moving group in the southern sky. In this work, we measure the rotation periods of 313 Tuc-Hor objects with TESS light curves derived from TESS full frame images and membership…

There is growing evidence that star clusters can no longer be considered simple stellar populations (SSPs). Intermediate and old age clusters are often found to have extended main sequence turn-offs (eMSTOs) which are difficult to explain…

We present stellar variability towards the young open cluster NGC\,6823. Time series $V$- and $I$-band CCD photometry led to identification and characterization of 88 variable stars, of which only 14 have been previously recognized. We…

Our ability to determine stellar ages from measurements of stellar rotation, hinges on how well we can measure the dependence of rotation on age for stars of different masses. Rotation periods for stars in open clusters are essential to…

We investigate the photometric modulation induced by magnetic activity cycles and study the relationship between rotation period and activity cycle(s) in late-type (FGKM) stars. We analyse light-curves spanning up to 9 years of 125 nearby…

We aim to identify the cluster members, estimate cluster properties, study the dynamical state of the clusters as a function of mass, trace the existence of dynamical effects in massive stars, and check for spatial patterns of members in…

The zero-age main sequence (ZAMS) is a critical phase for stellar angular momentum evolution, as stars transition from contraction-dominated spin-up to magnetic wind-dominated spin-down. We present the first robust observational constraints…

Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a…

Determination of stellar age is a crucial task in astrophysics research. Different methods are nowadays used either model dependent or based on calibrated empirical relations. The most reliable results are generally obtained when different…

We present stellar rotation rates derived from Transiting Exoplanet Survey Satellite (TESS) light curves for stars in Upper Centaurus-Lupus (UCL; ~136 pc, ~16 Myr) and Lower Centaurus-Crux (LCC; ~115 pc, ~17 Myr). We find spot-modulated…

The TESS mission delivers time-series photometry for millions of stars across the sky, offering a probe into stellar astrophysics, including rotation, on a population scale. However, light curve systematics related to the satellite's…

As more exoplanets are being discovered around ultracool dwarfs, understanding their magnetic activity -- and the implications for habitability -- is of prime importance. To find stellar flares and photometric signatures related to…

We determine rotation periods for 127 stars in the ~115 Myr old Blanco 1 open cluster using ~200 days of photometric monitoring with the Next Generation Transit Survey (NGTS). These stars span F5-M3 spectral types (1.2 $\gtrsim M \gtrsim$…

The ACS Survey of Galactic Globular Clusters is a Hubble Space Telescope (HST) Treasury program designed to provide a new large, deep and homogeneous photometric database. Based on observations from this program, we have measured precise…